COB efficiency Spreadsheets

klx

Well-Known Member
hi

how do I meassure cob efficenty..?
I have mean well HLG-185H-C1400A driver and 4 50w cobs...
In the shop they say I must buy some kind device that I put in the wall plug and then I put plug from the cob fixture to that device and that device will tell me if I supply the fixture with 200w (4x50w cobs)...or if I supplying the fixture with less or more I can on the driver with screwdriver dimm it...
or they talking about V instead of W...
I dont know but in the shop they have that device and they say it is realy importent

Am I correct about this?
What is that device and do I need it?
How will I now if my fixture is it at maximum efficenty?

please help me I know so litlle about electricity
I am guessing they mean one of these. So you can see exactly how much you are using from the wall when you dim the driver (or not)

https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU
 

Randomblame

Well-Known Member
It sounds they talking about a wall watt meter, Kill-a-Watt is a known brand. Walmart should have something similar for 10-12 bucks. But it is really not neccessary!
A HLG-185H-1400 with four 36v COB's(Cree, BLX, Citizen) running full 1,4A has around 200w net. and 220w at the wall, maybe a tad more.
Turn the built-in dimmer counterclockwise until it stopped and you get around 50% out of the A version(100-110w). With the HLG-185H-C1400 "B" version you can dimm it down to 6-10% output via an external dimmer pot.

I would rather invest the 10-15 bucks in a cheap lux-meter(0-100.000lx) from e3ay/am4zon. This is much more useful to set the optimal brightness on canopy level. 15-25.000lx in veg and 30-50.000lx in bloom is a good point to start with. Optimum ambient temp range with LED's is 80-85°F/26-30°C and keep the humidity in check, 55-60% is neccessary at 85°F/30°C. Do not get closer than 24" at the beginning and then slowly decrease it to 12-16" in full bloom. If you see yellow streaks on the upper leaves, the distance is probably too small(intense level above 50klux) and you need to dimm the light down. Or the air is too dry, which cause a too high vapor pressure inside the leaves, the plants will transpire too much and therfor take up more nutriens, espechially calcium which locks out magnesium and iron. The result looks almost the same(mg. deficit). In this case rise the light a few inches or dimm it down until the symtomes dissapear.
I prefer rather little too much distance and less light than too little and therefor getting bleaching and other deficits. Slowly approach to the optimum, the maximum intensity is slightly different for each strain! An equatorial sativa strain can surely handle more light than a rudelalis or indika strain growing in the tundra.

If you follow these tips, you will most probably have a successful first LED indoor season.
 
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pollen205

Well-Known Member
thanks guys so much for your answer...

I have so good light in my hand and I dont know nothing about it exept it is the best grow light in the world ...
I am really freaking out about burning them down with high electricity so I want to be extra carefuel...
I have 4 citizen CLU048 1212 GEN 6 3500k 80CRI...

so if I connect driver to cobs and put the driver with scredriver on minimum without wall watt meter , I am guessing that cobs will go on with minimum power and then when I dimm it with scredriver to maximum can I burn all my cobs ?
that is the version without wall meter...

So one more question in this subject...
I was told that cobs are best working on 50w but they go to 70w but then the efficenty arent in maximum....
So I am guessing that if I put my dimmer on driver to maximum every cob will recive 70 w ?
Is this correct?

So if I want to know exactly how many w I have from the wall I must buy wall meter...
So version with watt meter...
If I buy watt meter and I plugged my cob fixture to it I am guessing that will show me 200 w for my cob fixture...but how can I know for sure that each cobs recive 50w exactly..
And how to connect wall meter with mehanical timmer?

thank you so much for your help !!!
 

CobKits

Well-Known Member
I have so good light in my hand and I dont know nothing about it exept it is the best grow light in the world ...
fortunately they all are these days ;)

so if I connect driver to cobs and put the driver with scredriver on minimum without wall watt meter , I am guessing that cobs will go on with minimum power and then when I dimm it with scredriver to maximum can I burn all my cobs ?
that is the version without wall meter...
your cobs wont "burn" as long as you have proper heatsinks. 1212s are rated for over 100W max

So one more question in this subject...
I was told that cobs are best working on 50w but they go to 70w but then the efficenty arent in maximum....
So I am guessing that if I put my dimmer on driver to maximum every cob will recive 70 w ?
50 isnt "best". efficiency will continue to increase as you drop wattage
40 is more efficient than 50
30 is more efficient than 40
20 is more efficient than 30
10 is more efficient than 20
5 is more efficient than 10
etc

but then you have a lot less light. most people use 50W for the citi 1212s as thats a good balance of efficiency and chip utility

So if I want to know exactly how many w I have from the wall I must buy wall meter...
you can do it with a multimeter but then youre dealing with AC on bare wires which is more complex and less safe. the wall meter is worth the money, as is the cheap lightmeter suggested above. the latter more useful for making sure garden is uniform

If I buy watt meter and I plugged my cob fixture to it I am guessing that will show me 200 w for my cob fixture...but how can I know for sure that each cobs recive 50w exactly..
it wont. because youre not accounting for driver efficiency.

200W AC is about 185W to the cob. plants dont care if your cobs are 48 or 53W so dont stress about it. there is nothing "magic" about 50W.

but they go to 70w but then the efficenty arent in maximum....
So I am guessing that if I put my dimmer on driver to maximum every cob will recive 70 w ?
your driver cant give the cobs 70W because it is limited to 1400 mA

And how to connect wall meter with mehanical timmer?
timer can be before or after meter, its just a switch, it doesnt matter where you turn it off
 
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pollen205

Well-Known Member
thank you very very much cobkits...
very usuefuel information...

now I am sure that i cant burn my cob any how with driver and I have propper heatsink...

so plants dont care how many w i dimm it , I just need to buy lux meter and give canopy level 15-25.000lx in veg and 30-50.000lx in bloom
Am I correct ?

cobkits what wire do I need to use how many mm?
 
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pollen205

Well-Known Member
will it be problem if i wire cobs between with wire 1.5 mm
and then wire that cobs fixture with 1.5 mm cable in driver....
from driver I go with 2.5 mm copper cable to wall...

Is it ok?

thank you very much
 
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CobKits

Well-Known Member
thank you very very much cobkits...
very usuefuel information...

now I am sure that i cant burn my cob any how with driver and I have propper heatsink...

so plants dont care how many w i dimm it , I just need to buy lux meter and give canopy level 15-25.000lx in veg and 30-50.000lx in bloom
Am I correct ?

cobkits what wire do I need to use how many mm?
i dont know which holders you have but most use 0.75mm max

i dont mind helping but i gotta say its a bummer your vendor is offering you no support on this
 

pollen205

Well-Known Member
yeah I know...
ok i will go with 0.75 from cob to cob

one more qustion cobkits...

is it better to put driver outside growbox or inside...
 
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CobKits

Well-Known Member
doesnt matter. in series at 1400 mA you can run a good length of wire without much loss

since it an 'A' driver yo want to put it where it is accessible

not to pick, but in the interest of keeping threads tidy can you ask your build questions in one of the two threads you started about it?

none of this stuff has anything to do with COB efficiency spreadsheets and people love to help here but chatter in random places makes it difficult for people to find stuff later

also 0.75mm is area, diameter is 1mm aka 18 GA
 
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